The effects of electron beam and gamma-ray irradiation on the optical properties of InGaAs/GaAs quantum dot (QD), quantum well (QW), and bulk structures, which were grown by metal organic vapor phase epitaxy, have been investigated. Optical properties of all the structures were degraded by both kinds of irradiation. Electron beam irradiation caused a larger reduction in the photoluminescence (PL) intensity and carrier lifetime of the samples than gamma-ray irradiation. Also, red-shift of the PL peak was observed in almost all the irradiated QD and QW structures. Comparing the different structures, the QD structure showed the best radiation resistance.